Almost every city and town contains a site with an underground storage tank (UST) that is affected by petroleum contamination or impacted by the perception that contamination exists. In addition to the almost uncountable number of abandoned gas stations, UST sites also include things like idle manufacturing facilities or moribund commercial areas that dealt with oil in some way. The list is as long as it is diverse. Thus, the challenge of petroleum contaminated brownfield sites is significant. This report, the final in a series exploring the issues and opportunities of petroleum contaminated brownfield sites, describes the progress states and communities have made in addressing UST situations, lays out lessons learned from the pioneer “UST field pilots,” and re-examines the detailed findings and recommendations of the landmark report, Recycling America’s as Stations (RAGS), published in 2002 as the original UST field initiative was making the transition to a component of the EPA brownfields initiative.